Which type of friction causes a sky diver's acceleration to change as she falls?

A.

Sliding

B.

Rolling

C.

Fluid

D.

Static

5.

Two forces act on an object. One force has a magnitude of 10N and is directed toward the north. The other has a magnitude of 5N directed toward the south. The object experiences a net force of

A.

5 N south

B.

15 N north

C.

50 N north

D.

5 N north

6.

A reference point for determining position and motion could be

A.

The Earth's surface.

B.

A building.

C.

A moving object.

D.

All of the above.

7.

The distance traveled divided by the time it took to travel that distance determines an object's

A.

Speed.

B.

Acceleration.

C.

Weight.

D.

Force.

8.

You are in Chicago, IL. You decide to head south to Austin, TX. In one hour, you travel 80 km. Your velocity is

A.

80:1

B.

80 km

C.

80 km/h

D.

80 km/h south

9.

A car traveling 20 m/s south enters a new highway going east at 20 m/s. The car has

A.

Decreased its distance.

B.

Changed its speed.

C.

Accelerated.

D.

Not changed its velocity.

10.

Acceleration is a change in

A.

Speed.

B.

Velocity.

C.

Direction.

D.

All of the above.

11.

When velocity decreases, this could be referred to as

A.

Acceleration.

B.

Deceleration.

C.

Negative acceleration.

D.

All of the above.

12.

Which of the following is NOT an example of a force being exerted?

A.

Pushing a door open

B.

Typing on a computer keyboard

C.

Sitting in a chair

D.

None of the above

13.

A friend is helping you to arrange your bedroom furniture. You exert 25 N of force to push the foot-end of the bed while your friend exerts 20 N of force pulling on the head-end of the bed. The net force being used to move the bed is

A.

5 N forward

B.

20 N forward

C.

25 N forward

D.

45 N forward

14.

What is the net force when you combine a force of 7 N north with a force of 5 N south?

A.

2 N north

B.

2 N south

C.

12 N north

D.

12 N south

15.

Balanced forces applied to an object

A.

Produce a net force of zero.

B.

Change the direction of a moving object.

C.

Cause an object at rest to start moving.

D.

Produce negative net force.

16.

A good rule to observe when around a swimming pool is "no running." The deck around the pool becomes very slippery to walk on when wet due to

A.

Sliding friction.

B.

Rolling friction.

C.

Fluid friction.

D.

Static friction.

17.

One way to increase friction is to use

A.

Water.

B.

Sand.

C.

Oil.

D.

Wax.

18.

The air that comes out of the tiny holes of an air-hockey table is an example of

A.

Net force.

B.

Friction.

C.

Gas lubricant.

D.

Liquid lubricant.

19.

An object's velocity remain constant when its __________ do not change.

A.

Speed and direction

B.

Speed and time in motion

C.

Time in motion and direction

D.

Distance traveled and time in motion

20.

Your class and another class have a tug-of-war contest. For your class to win, your class must

A.

Create a balanced force with the other class.

B.

Have a greater force in the direction opposite the other class.

C.

Have a greater force in the same direction as the other class.

D.

Create a net force of zero with the other class.

21.

You have made a house of cards on top of your table. Suddenly, a gust of wind blows through an open window and your house of cards comes tumbling down. The wind applied ______ to your house of cards.

A.

Friction

B.

A balanced force

C.

An unbalanced force

D.

A gravitational force

22.

When applying brakes on a car or a bicycle, you are using _______ friction to stop.

A.

Sliding

B.

Rolling

C.

Fluid

D.

Static

23.

_______________ opposes motion between surfaces that are touching. (Friction or Gravity)

24.

Forces are expressed in _______________. (newtons or mass)

25.

A _______________ is determined by combining forces. (net force or newton)

26.

Any change in position over time is an example of _______________. (motion or acceleration)

27.

The newton is the SI unit of _______________. (force or mass)

28.

When observing an object in motion in relation to an object that appears to stay in place, the object that appears to stay in place is a _______________. (friction point or reference point)

29.

Total distance divided by total time gives ab object's average _______________. (speed or acceleration)

30.

The speed of an object in a particular direction is an object's _______________. (speed or velocity)

31.

A push or a pull is a _______________. (friction or force)

32.

When the net force on an object is not zero, the forces on the object are _______________. (unbalanced or balanced)

33.

When a force is applied to an object but does NOT cause the object to move, _______________ occurs. (static friction or sliding friction)

34.

_______________ are substances that are applied to surfaces in order to reduce the friction between them. (lubricants or friction)